Glass cutting



Dec. 3, 1929. F. N. CAMPBELL ET Ax. 1,738,229

GLASS CUTTING.

Filedneo. 1o, 192e ities. 3, lQZ@ cierran stares tdi/3am@ FURMAhl N.CAMPZBELL, OF NEW HAVEN, ANI) JULES llIYATT, OF EAST HAVEN, OI\l'-NECTCUT, ASSGNORS T BESSIE GREGG, 01" FOREST HILL GARDENS, NEW YORE;

GLASS CUTTING appncanon niet neeember 1o, i928. sence. no,

` of cellulosic or gelatinous material are placed to prevent shattering,etc. l

Heretofore it has been impossible to sever or trim such laminated glassaccurately or economically after the laminations have been securedtogether. The difficulties in cutting or trimming such glass areencountered by reason of the widely different characteristics of thelass and the material for preventing shattering. That i's, any ordinarymeans which Will crack or sever the glass is not suited for severing thecellulosic material. Vice versa,y any medium for softening or euttingthe cellulosic'material interferes With `lthe cutting of the glass.

In addition to the cutting of laminated glass, certain features of thisinvention are applicable to the cutting of single layers of Cr ass.

n Various further and also various more specitic objects, features andadvantages Will clearly appear from the detailed description givenbelowr taken in connection with the accompanying drawings which form apart of this specification and illustrate, merely by way of example, oneembodiment of the invention.`

According to one embodiment of the presentinvention, the tivo sheets ofglass at the opposite sides of the cellulosic lamination may be firstcracked along the desired line of separation successively orsimultaneously by a suitable process, such 'for example as thatdisclosed in our Patents' Nos. 1,720,883 and 1,719,588, and in ourcopending application Ser. No. 223,864. However, according to certainphases of the invention, other cracking methodsl` might be used, suchfor example as the Well known use of a diamond or steel wheel.

After this cracking operation, the glass at one side of the line ofseparation is preferably heated to a suitable temperature to soften orto` an extent to reduce the adhesion of the layer of cellulosic or likematerial and the adjoining glass surfaces, vvhereioj.7 within limitedzone at least along one ,side of the line of separation, the adhesion ofthe cellulosic material to the glass has loosened, or the cellulosicmaterial becomes relatively plasticA Thereafter the area of glass at-theside of the line of separation Which has not been hcated, may be fixedon a suitable stationary support While a force is applied to the area ofglass at the other side of the line of separation, so as te draw. thelatter area apart from theI stationary area.r Such `force may hereferably applied in a direction substantial y perpendicular to the lineof separation and along the plane of the glass. Under certaincircumstances it may be found desirable to retain,

the heated area of glass in a stationary position While the relativelylunheated area' is drawn away therefrom.

By following out this process, it Will be found that the cellulosicmaterial along a zone adjacent the line of separation and at the sidewhich has been heated, will be pulled free of the heated areas of glassand Will adhere t-o the edge of the unheated section, thus leaving thecellulosic material at the edge of the unheated section free of anyirregularities or torn out portions. The protruding or eX- posed edge orZone of iellulosc material may be readily trimmed ot or eliminated bysuitable cutting or melti; g" means. y

In Fig. 1 a layer of laminated glass is indicated comprising a top glasslayer 10, 10', an intermediate layer of cellulosic or other bindingmaterial 11, and a bottom 'layer of glass 12, 12. The glass is shownsupported on a pair of spaced supports 13 and 14:, which may be of thetype disclosed in our copending applications above referred to. A pairof electrical cutting devices are indicated at l5` liti at 17 of Fig. 2,whereupon the relative positions of the'glass andthe cutting means maybe moved, for example, as shown in Fig.

^ 2, so that the heating devices ofthe cutting vmechanism may heat thearea of glass at. one

side of the line of separation at 17 -to a temperature higher' than thatvof the-glass at the other side of the line of separation. 'llha't is,for example, vas shown-in Fig. 3 the hot cut` ting device may be placedalong a line 18,

leaving va narrow strip l19 between the two successive positions of thecutting element.

Thereupon the 'glassadjacent the line 18,

l and particularly the glass'along the strip 19,

become heated, whereas the glass to the right ofthe line 17 will remainrelatively cooler.'

Thereupon the area of vglass l() may be readily separated from thearea'lO in the manner above described. With such separ ation thecellulosic or other binding material along the strip 19 being.relatively more plastic, will give way and may be separated from theadjacent areas of glass of the piece 10', sothat the narrow strip ofce'llulo'sicI to be of greater importance to secure-a sub;v

stantial relative dierence of temperature between the li'ea'ted area andthe unheated area as above referred to. -That is, although the area atone side ofthe line of separation has been' referred to above -as beingun-l heated, this may be taken tomean relatively unheated,4 as comparedwiththe vhotter area of glass at the'other side of the line ofAseparation.

L In our above mentioned patent applica- I tions, apparatus is disclosedin such form as to be v'applied to one surface of glass. It will beunderstoodthat such apparatus in connection with the present inventionmay be.

substantially duplicated, one set of heating elementsbeingapplied to`each ofv the two outer surfaces ofthe laminated glas`s'along. ting beingindicated at-1.91520@ the `line of separation as indicatedin Figs. 1 and2; in' fact it has been 4found desirable under certain circumstances touse. sets of heating elementson t-he two oppos1te surfaces-- of sin lesheetsn ffrlass as well'as'laminated c g o 2" 7 detallwlth respect tocertain particular preglass, to secure rapid and accurate separation ofthe glass along the desired line. The above describedprocesses areparticularly desirable for use in 'connection with the cutting of sheetsof glass', either singleor laminated, of irregular shapes includingthose with curved as well as straight or angular edges, as for instancelautomobile windshields lor windowspf singleor laminated l,glass Wherethe process is used in conjunction with electrical 'heating and cuttingmeans, for cutting single sheets of glass as disclosedin-our above,mentioned patent applications, the product is particularly desir-` ablefor-use in the making'of laminated glass in that the edges of the glassare free from chips and flaws', lwhich it is believed' con# tributelargely to the breakage of laminated glass, inasmuch as such chips andflaws (as occur with the cutting of glass with diamonds a-nd steelwheels) appear to, provide starting points for cracks and shatteringwhen the laminations are subjected to pressure in the .tates theaccurate cutting of glass,;according.

to this general method, particularly Where 'theglass is of substantialthickness. y

It will be understood that afterthe lami nated glass vhas`been crackedalongthe line of separation, such line of cracked separation serves asan effective insulating barrier -between the relatively hot and thecooler areas of the glass, whereby the 4-relative differenceoftemperature of these two areas may be sharply defined, thus insuringrelease of the cellulosic material fromthe section of glass `,which istrimmed olf while the cellulosic ma-v a'terial remains in normalconditionloetween the laminations of glass of thearea which is being cutto measure.- f v I-fdesired, the area of glass which'has been relativelyheated in --th'e above described.` process, may in part be reclaimed byretrim-V ming the same in v,a'm-an'ner similar 'to the labove describedlprocess; thereby, for ex-l ample, a largearea-'bf laminated 4glass maybe cut into sections as desired without any wasteglassfbetween sectionsother than af narrow strip, from. which .thecellulosic 'ina -115 terialhas been-wholly or'partially removed. This is shown Fig-6, a separationof the cellulosic material at the second line of cuti' Y. Our. copendingapplication Ser. .TNQ 373,245, vfiled "June 24, 1929',v embodies claimsto 'various fea-tures above referred to.

1 While the invention hasbeen described in'- invention, thatvariouschanges'and modifica! tions maybe made without departing'from' vthespiritand scope of the invention and 'it is intended therefore in theappended claims to I at one side of said line of separation atemperature different from that of the glass at the other side of theline of separat-ion, whereby one of said-areas of glassmay be separatedfrom the other without disturbance of the shatter preventing materialwithin said other area.

2. Process of severing laminated glass comprising a plurality of layersof glass between which material for preventing shattering is interposed,which comprises cracking the layers of glass along the desired line ofseparation by applying electrically heated conductors thereto, andthereafter creating in the glass at one side of said line of separationa temperature different from that of the glass at the other side oftheline of separation, whereby one of said areas of glass may be separatedfrom the other without disturbance of the shatter preventing materialin4 one of said areas.

3. Process of severing laminated glass comprising. a plurality of layersof glass between which material for preventing shattering is interposed,which comprises cracking the layers of glass along the desired lineofseparation by applying electrically heated conductors theretp, andthereafter by the use of electrically heated conductors, creating in theglass at one side of said line of separation a temperature diierent fromthat of vthe glass at the other side of the line of separation, wherebyone of said areas of glass may be separated fromthe other withoutdisturbance of the shatter preventing material in one of said areas.

4. Process of severing laminated glass coniprising a plurality of layersof glass between ywhich material for 4preventing shattering isinterposed, which comprises substantially simultaneously cracking thelayers of glass along the desired line of separation andthereaftercreating in the glass at one side of said line of separation atemperature different from that of the glass at the other side of theline of separation, whereby one of said areas of glass may be separated'from the other without disturbance of the shatter preventing materialin said first named area.

5. Process of severing laminated glass, comprising a pluralityo layersof glass between which shatter preventing material is interposed, whichcomprises dividing the lavers of glass along the desired line ofseparation, and thereafter separating the divided portions by removingfrom one otsaid portions a narrow strip ofthe shatter preventingmaterial,` together with-'the other portion of laminated glass, leavingthe shatter pre venting material intact between the edges 'of said lastnamed portion.

. 6. Process of severing laminated glass com` prising a plurality oflayers of glass between.

which 'shatter preventing material is interposed, which comprisesdividing rthe layers of glass along the desired line of separation andthereafter separating the divided por-- tions by removing from one ofsaid portions a -narrow strip of the shatter preventing comprisescracking the layers of 'glass along the desired line of separation,releasing the shatter preventing binding material in -re- .materiahtogether with the other portion of l spect to the glass at one side ofsaid line only, and" thereafter separating the severed areas of theglass. y 8.' Process of cutting laminated glass which comprises crackingthe layers of glass along thedesired line of separation, releasing theshatter preventing binding material in respect to the glass atone sideof said line only and separating the severed areas of the glass, andthereafter trimming away the protruding strip of shatter preventingmaterial from the severed ortion ofglass at the other side of the lineoseparation. In testimony whereof wehave signed our names to thisspecification.

FUR-MAN N. CAMPBELL. JULES MYATT.

` .sentinelle lon connection.

fili-IRMAN N. millenni. man.

It; lierebv certified" thiat;,errorl appears in the printedspeeification of' ytlie above numberedfpa't'ent reqnii-ingcorrection asfollows: "lingeV l, if-ter linev 33, -v insertl the paragraphs,,"Theinventionfeonsists-in..Such novel features, .arrangements,vapparatus, methodsmandi,products'asjsliovvri, deseribed, 'andclaimed inJconnection wift-lifthe embodimentsof the' invention vherein disclosedby way of .example orily.".fl

. 'Inthedi'awings, Figs, and'Z-4 indienne somewhat sclhemnt-ially thearrange.

ment 'of-Aanparats-ffor-apply'ingthe invention toftlle cut-ting of'laminated gloss;

' Figs. 3, fand)5f-indicate areas .of laminated glassnseutvaccordling'to tine 'process ol 'the invention; f., 'Fig'. 56 is aviewgsimilar to llig. 5, but indicating a piece of laminated'gl'asswhieh hasbeentwice'- ontV along closely adjacent lines; and fFig. 7 i'mli'catesv the use of the 'npparatnshereof as applied -to thecutting' of singles'heets of glass.; and that tliesaid letters lntentshouldbe read Willa in, meenemen-leef.

"these corrections therein that the same mayeonlorm tor the'reeord oitire case signed'va'ni sealediiniettato-nay:einem@ fl.- n. noso.'

i. Mmm,

A' (Seal) j. Acting Commissioner ol Patents. Y

